Dymarskii, Y.M. (1996) “On manifolds of eigenfunctions and potentials generated by a family of periodic boundary-value problems”, Ukrains’kyi Matematychnyi Zhurnal, 48(6), pp. 771–781. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5277 (Accessed: 10 April 2025).